is 



I'lIYSItii.ouv OF MOSCLES AM> NERVES. 



to it, \vlicii it, is in a quiescent state ; flic other, \\hen 

 it is active. When a quiescenl mu-de i- brought int.: 

 an active condition liy irritation, it assumes a form 

 which is no longer natural to it, it strives to attain the 

 latter, and shortens until it readies it- new form, which 

 i- then natural to it. It' the muscle is extended liy a 

 weight, and is then irritated, it immediately contracts; 

 but only to that length which represents the exten- 

 sion by the attached weight, proper to its ne\v form. 

 Let us imagine that A //, in ti<j. 16, is the length of 



It "' I! // 



I-'K,. Id. A i .1 1.1: A n.iN IN 1. 1.. \snci rv I 



- JC 



y 



cnsTKAci I,N. 



the muscle when ijiiiescent and unburdened, and that 

 A I i- the length of the mn-de when active and un- 

 burdened. Then the inn-de. if it is irritated while 

 unweighted, will shorten to the extenl represented bv 

 J />' -- A 1> -.-. l> II; /> I! is. therefore, the height ,,f 

 e|e\atiui of the unweighted muscle. If a weight // is 

 attached to the nni-de, the latter in its inactive condi- 

 tion will lie extended to a certain degree (//'</'); so 

 that its length will now be J /,'-}- /,",/'= J ' /,". On 

 being now irritated, it contracts and assumes a length 



